Haddox started to work as production assistant and production driver in the movie industry. He worked as post-production assistant on the television series Me and Mom (1985, starring Henry Darrow) and on the horror film Demonstone (1989). As production assistant he worked on the television drama Children in the Crossfire (1984, with camera operator Lowell Peterson), the television series Partners in Crime (1984), the television drama Kids Don't Tell (1985, with Robin Gammell, Bob Minor, and Branscombe Richmond), the comedy Bad Guys (1986, with Eddy Donno and Gene LeBell), the action drama Eye of the Tiger (1986), the science fiction film Programmed to Kill (1987), and the science fiction thriller Disaster at Silo 7 (1988).

Haddox also worked as production driver on the comedy He's My Girl (1987), for Whoopi Goldberg on the crime comedy Homer and Eddie (1989), and for Brad Pitt on the drama Seven Years in Tibet (1997). Following a six year connection with the television series Rescue 911 as Front Office Receptionist/ Story Line Editor between 1990 and 1996 Haddox became an assistant accountant and worked on projects such as the Academy Award winning drama American Beauty (1999), the comedy The Extreme Adventures of Super Dave (2000), the science fiction thriller Equilibrium (2002), the science fiction film A Sound of Thunder (2005), and the drama Tristan + Isolde (2006). He then worked as accountant on the fantasy film The Forbidden Kingdom (2008) and more recently as key assistant accountant on the action film The Man with the Iron Fists (2011).